Jawabanmu

2014-06-02T14:34:18+07:00
Lp = 2 . Lalas + Kalas . tprisma
Lp = 2 .  \frac{1}{2} . 15 . 20 + (15 + 20 + 25) . 12
Lp = 300 + 60 . 12
Lp = 300 + 720
Lp = 1020 cm²